It is frequently desirable to isolate all or a portion of the user's skin from the outside environment, either to isolate the skin itself or to isolate an orifice such as the user's ears, eyes, nose or mouth. Such isolation may need to be either airtight or watertight, and such terms are used interchangeable herein. Goggles provide an example of the types of problems encountered in the prior art regarding such isolation. Goggles are commonly used to separate or isolate the eyes and face of the user from the nearby environment. For example, swimming goggles are utilized to separate and protect the eyes from water thereby allowing the swimmer to see clearly within and find a path through the water. Other goggles, such as protective goggles, are utilized to prevent exposure of the user's eyes to toxins or contaminated material, such as blood or harmful gases or materials. Goggles may also be used to protect the eyes from harmful or undesirable environmental conditions, such as cold or dry air or sand or dust in the air. Goggles may also be used to retain a particular fluid or gas near the eyes.
Traditionally, goggles have been made with a rigid or semi-rigid frame, which was directly compressed against the skin of the face by use of an elastic strap extending around the user's head. Frames were poorly compliant and did not conform well to the user's face at a comfortable pressure. This often resulted in an incomplete seal that was not watertight. In order to create a better seal, the goggles could be more firmly compressed against the face. This created discomfort and irritation to the face, facial bones, and delicate underlying blood vessels.
The problem with rigid or semi-rigid frames was partially solved by utilizing softer frame materials and by placing a pad or gasket between the frame and user's face. These pads were made with various materials, such as rubber or plastic, which were softer and more compliant than the frame materials.
There are, however, problems with existing goggles that utilize a pad or gasket. Existing solid pads have limited ability to conform to the variations in the human facial bone structure. To create a watertight seal, large compressive forces often must be applied to the frame to force the existing solid pad against the user's face. In some individuals, the pressure and resulting compression can be tolerated, but in others their skin is too delicate to comfortably withstand the large compressive force required. For these individuals, discomfort precludes their ability to successfully use this form of goggles. For other individuals, the bone structure is not compatible with the shape of goggles and water and air leaks occur even with high compressive forces.
Less rigid pads or gaskets made of foam rubber or other foam plastics have also been used. These pads consist of plastic or rubber material that contains numerous tiny air spaces and can be readily compressed at low pressure. The foam pad is better able to conform to the facial bone structure. Although foam pads are generally an improvement over existing solid pads, there is a limited capacity for the foam pads to conform to the delicate facial skin and bone structures. Moreover, the compressive forces are not symmetrically distributed throughout the pad. This results in pressure points where prominent facial bones meet the pad. If the pad does not conform fully to the contour of the facial bones, the result is a leak where air, water or other material may pass between the pad and the user's face. Such leaks can often, but not always, be reduced or eliminated by increasing the pressure applied by the frame upon the face. If the foam is thick enough and enough pressure is applied, the foam pad will usually fill in the gaps between the face and frame. When tightly compressed against the face, however, the foam pad takes on more of the characteristics of a soft rubber of plastic pad. Therefore, these foam pads suffer from many of the same limitations of discomfort and damage to the facial skin and blood vessels as do the more rigid solid pads.
In addition, because foam has air pockets or pores, it cannot be fully cleaned after each usage. As a result, bacteria and fungus grow in the air pockets in the foam. Such bacterial and fungal growth can serve as a source of eye and skin infections and can be a hygiene and health risk.
Attempts have been made to vary the shape and size of the frame of goggles in order to obtain a more successful seal with the user's face. This has been useful for some individuals, but because of the human variability in facial bone structure, this is unsuccessful for many individuals. There are a limited number of shapes that can be cost-effectively manufactured and these shapes do not necessarily conform to the numerous variations in bone and facial structure.
The above-described problems with prior art goggles are illustrative of the problems inherent in creating an airtight or watertight seal over a portion of the user's skin. The previous devices used to form such seal normally result in (a) discomfort to the user due to the amount of pressure applied, (b) a seal that is not consistently and reliably airtight or watertight, or (c) an ordinarily expensive sealing mechanism.